WPCL 2BJ|x ` H   x|@  6'6' N  `  @  <AP IX61E NN  `  @  <AP IX61E N I (3202)  I (3202)    >ANNEX B A 5(to Recommendation G.771) A /LCN physical configuration attributesă A   HThese LCN physical configuration attributes represent the requirements an administration imposes on the configuration of the whole of the particular LCN to be designed. In the PQ(lcn) protocol suite selection process (5.3.2) these LCN physical configuration attributes will not only influence the choice of PQ(lcn) protocol suite, but also determine the type and quantity of mediation devices needed. HDuring the design of the LCN the administration may also consider the number of ports per configuration and the number of such configurations that can be served by a particular mediation device that implements the selected protocol suite. HTogether with the distribution of network elements over space and the cascadibility of the mediation devices this leads to the layout of the LCN. HHowever, such mediation device design characteristics are beyond the scope of this Recommendation. HSome LCN physical configuration attributes are: 1.HNumber of NE ports HSpecifies how many network element local communication ports are to be served by an LCN (including mediation devices). HDescriptor: (ports) small < 32 medium > 32, < 256 large > 256, < 2048 very large > 2048 2.HConfiguration HSpecifies the configuration to be used for the LCN. HDescriptor: star; bus; ring. 3.HNumber of ports per configuration HSpecifies how many ports are to be interconnected within a single configuration (star, bus or ring) of the LCN. HFor a star configuration count the number of branches, as one port per branch is implicitly assumed. For masterslave protocol suites for the bus or ring configuration, the master is excluded from the count of ports per configuration. HDescriptor: (ports) small < 8 medium > 8, < 32 large > 32, < 128 very large > 128 4.HCommunication distance HSpecifies the distance to be bridged within the LCN. HDescriptor: (meters) very short < 10 H  short > 10, < 100 medium > 100, < 1000 long > 1000 5.HCommunication environment HDescriptor: withinrack on the same floor inbuilding out of building HThe need to provide further attributes is for further study.  _(Ԍ HLANNEX E HO HC(to Recommendation G.771) HO H?LCN protocol selection attributesă HO HThese LCN protocol selection attributes summarise the capabilities of the individual PQ(lcn) protocol suites for use in the LCN protocol suite selection process described in 5.3.2. Note Abbreviations are given for each allowed attribute value as a key to TableF.5/G.771. HThe protocol selection attributes are: HAt layer 1: H configuration S: star; B: bus; R: ring H number of ports per S: small < 8 H configuration (ports) M: medium > 8, < 32 H L: large > 32, < 128 H VL: very large > 128 H physical medium SP: screened pair; TP: twisted pair CP: coaxial pair; OF: optical fiber H O: other H transmission mode S: synchronous; AS: asynchronous; HD: half duplex; FD: full duplex H operating speed 1200, 2400, 4800, 9600, 19200, H (bits per second) 64000, 128 000, 1 000 000 H communication distance VS: very short < 10 H (meters) S: short > 10 < 100 H M: medium > 100, < 1000 H L: long > 1000 H communication environment WR: withinrack; OF: on the same floor; H IB: inbuilding; OB: out of building H availability (%) L: low H M: medium under study H H: high HAt layer 2: H data link connection CO: connection oriented; CL: connection less. H data link initiator M: master; AP: all participants H data link address size S: small < 8 H (addresses) M: medium > 8, < 32 H L: large > 32, < 128 H VL: very large > 128 H receipt confirmation Y: yes; N: no H maximum frame size S: small < 256 H (octets) M: medium > 256, < 4096 H L: large > 4096 H max: frame frequency per L: low < 1/60 H port (frames per second) M: medium > 1/60, < 1 H H: high > 1 H max: frame transmit delay S: short < 0.1 H (seconds) M: medium > 0.1 < 1 H L: long > 1 H error detection N: none; P: parity; CS: checksum (n) M$NN%O CRC: cyclic redundancy check (n) H hamming distance 1, 2, 3, 4, n H error recovery N: none; R: repetition; C: correction HAt layer 3: H LCN network size S: small < 32 H (ports) M: medium > 32, < 256 H L: large > 256 < 2048 H VL: very large > 2048 H routing Y: yes; N: no H (un) packing Y: yes; N: no H connections N: none; P: permanent; SW: switched H priority Y: yes; N: no HThe other layers are for further study.